The use of silicones as conditioning agents in cosmetic formulations is well known and widely documented in the patent literature. Generally, dispersed droplets of the silicone oil are suspended in the composition, which is then applied to the hair to deposit the silicone material on the hair shaft.
A problem encountered with silicone shampoo formulations is that the conditioning performance may be insufficient for many people, particularly in regions such as Japan and South East Asia where consumers desire a high level of conditioning and a "weighty" feel to their hair.
We have now found that improved conditioning performance from a surfactant-based shampoo composition can be achieved by the inclusion in the shampoo composition of a specific combination of silicones, namely amino functionalised silicone and high viscosity non-amino functionalised silicone.
U.S. Pat. No. 5,198,209 (Amway Corp) published 1993 discloses a conditioning shampoo with cleansing surfactant and a combination of dimethicone and trimethylsilylamodimethicone, and mentions that superior conditioning benefits are obtainable when an aminofunctional silicone is used with polyalkylsiloxane (e.g. dimethicone) or polyalkylarylsiloxane. For optimum conditioning the viscosity of the dimethicone is said to range from 30,000 to 100,000 cst.
L'Oreal EP 0 811 371 describes cleansing compositions for hair comprising surfactant and a conditioning system comprising (i) cationic polymer (ii) aminofunctional silicone (iii) insoluble non-aminofunctional silicone of viscosity less than or equal to 100,000 cst. The composition is said to improve wet and dry combing, manageability, softness and smoothness. This document specifically teaches against replacing 60,000 cst dimethicone with 300,000 cst dimethicone in a composition comprising amodimethicone.